Cam-controlled workholder



Sept. 6, 1955 c. A. ULFVES CAM-CONTROLLED WORKHOLDER 2 Sheets-Sheet 1 Filed July 23, 1953 INVENTOR. KARL A. ULF'VES llll I III]! FTq. 3

Sept. 6, 1955 c. A. ULFVES CAM-CONTROLLED WORKHOLDER 2 Sheets-Sheet 2 Filed July 25, 1953 4 l w fix 0/0 A 2m Fig/Z BY IN VEN TOR. 4. UL I s 5 United States. Patent 2,716,851 CAM-CONTROLLED WORKHOLDER Carl A. Ulfves, Worcester, Mass. Application July 23-, 1953, Serial No. 369,863

4 Claims. (Cl. 51-432) This invention relates to cam cont'rolled workholders and is an improvement on' the devicev shown in my prior United States Patent No. 2,576;707, issued November 27', 1951. I I

In general, the objects of the present invention are siinilar to those in my patent, but in the present case the invention contemplates the use of extra cams which increase the usefulness of the device and allow the grinding of tapers, angles, ovals, eccentrics or polygonallyshaped figures and practically anything convex, which could not be done by the mechanism of my prior invention.

In general, the construction of the present invention is similar to that shown in the patent, but includes the provision of several additions and special cams and cam combinations as will appear more fully hereinafter.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a top plan view of the device showing in dotted lines the addition of a novel cam;

Fig. 2 is a view in side elevation, parts being broken away and in section;

Fig. 3 is an end elevation thereof;

Fig. 4 is a section in simplified form through the device of Fig. 1;

Figs. 5 and 6 illustrate the use of polygonally-shaped, cams; and

Figs. 7 to 13 inclusive illustrate various aspects of other cams that may be used to grind difierent shapes.

A base or table 10 is provided upon which the semicircular cams 12 and 14 may be slidably arranged with relation to a removable centering plug or the like 18 which corresponds to that at 20 in my prior patent above identified. These semi-circular cams are provided with means for clamping them in desired position with reference to a. top plate 20 upon which is mounted a V block or the like 26 adapted to hold the work, which as shown in Fig. 1, ordinarily comprises a piece of round stock W.

The cams 12 and 14 guide the movement of top plate 20 with reference to a fence or the like 28 and utilizing the non-peripheral side of the grinding wheel, the Work W will be ground to the order of the earns 12 and 14 except that the work is of much smaller size and is therefore extremely accurate.

Whereas the semi-circular earns 12 and 14 will provide for circular and rectangular shapes (by being reversed) as well as some oval shaped work, they will not provide for angles, eccentrics, etc. and ellipses, and therefore in the present case I provide an additional cam member which is indicated at 30. This is a special cam which may be circular if desired (see Fig. 11), this cam having for instance a diameter slightly larger than the combined semi-circular cams when butted together.

The cam 30 is superimposed relative to earns 12 and 14 and over-rides the same as to contour grinding in the regions where cam 30 extends beyond the lateral edges 2,716,851 Patented Sept. 6, 1955 2, of cams 12 and 14 as at 32 and 34, the semi-circular cams being spaced. The cam is therefore a combined cam and looking at Fig. 11, the semi-circular cams are effective to guide the device against fence 26 at the right and left-hand areas thereof, but at the lower and upper areas the cam 30 is the guiding factor and these cams merge smoothly into each other at points 36.

A great many variations of this particular camarrangement may be made. One of the semi-circular cams may be moved completely under cam 30 as in Fig. 13 and therefore becomes inoperative, in which case an eggshaped contour will be ground, whereas in the case of the cams arranged as in Fig. 11, a generally elliptic contour will be the result. It is easy to substitutecircular cams 30 of different diameters and the cams 12 and14 may of course be adjusted in and out relatively to cam 30 to the degree desired for the results postulated.

Referring now to Figs. 5 to 10, the top plate has associated therewith polygonal earns 40' and 42, the polygonal cams being provided with holes 44, 46, respectively. The cams 40 and 42 are provided with center holes 48 by which they may be set upon and arranged with respect to plug 18 and the work being clamped as before in the V block 26, the device is used in actually the same manner as heretofore described, in the case of Fig. 5 grinding a hexagon, and in the case of Fig. 6 an octagon.

A pin 50 is provided for entry into a hole 44 and 46 and a corresponding hole in the top plate 20 by which means the polygonal cams are locked with relation to top plate 20. The cams are superimposed and held in oriented relation by the pin 50 in both holes. By removing the pin 50 and placing it in different holes, other polygonal figures of multiple sides are ground.

For instance, looking at Fig. 6, the octagon having been ground, the pin being moved 22 /2 to the location 52, the corners will all be ground off and a sixteen-sided figure results. This concept is extended as in Fig. 5, where is shown a plurality of diiferent holes 54 by the use of which in combination with pin 50, polygonal shapes of different numbers of sides are provided.

It will be seen from the above that this invention provides an extra cam plate which may be as shown in Fig. 11 or in Figs. 5 or 6, and specially irregularly shaped cams can be made up easily to grind the desired shape. Also it is pointed out that the larger the cam in relation to the work, the smaller the relative error and although many combinations may be achieved by the original semicircular cams, the present invention expands the device in its usefulness to a great many other applications, as tapers, eccentrics, etc.

By applying the conventional sine bar to the workholder, tapers, angles, and other contours may be achieved and the cams are all easily fastened in position by means of screws or bolts 54 which may pass through slots 56, or other equivalent orienting means, allowing considerable diversifications of position.

The cam 30 is preferably provided wtih a center stud 58 which may fit into the center hole 60 in the top plate 20 and of course the polygonal cams may be provided with the same arrangement for centering them. Also it is pointed out that more holes may be provided in the polygonal cams if desired.

The present device is used to accurately form and grind tools and punches in all shapes desired, including angles, rectangular, tapers, eccentrics, etc.

I claim:

1. A device of the class described comprising a base plate, a movable workholder on the base plate, a cam on the workholder, means providing an axis for rotation of the cam on the workholder, means locking the cam to the workholder in rotatively adjusted position thereof, a relatively stationary fence to be engaged by the cam as the workholder is moved, said cam being polygonal, a plurality of holes in the polygonal cam and a hole in the workholder, and dowel means insertable in aligned holes for rotatively positioning the cam relative to the workholder.

2. The device of the class described comprising a tablelike base, an upstanding fence thereon, a semi-circular cam on the base in free sliding engagement therewith for engagement with the fence at its edge and a second cam superposed relative to the first cam and having edges thereof extending beyond certain portions of the edges of the first-named cam for engagement of the extending edges with the fence, and a workholder on the cams free of the fence.

3. The device of the class described comprising a tablelike base, a fence thereon, a semi-circular cam on the base in sliding engagement therewith for engagement with the fence at its edge and a second cam superposed relative to the first cam and having edges thereof extending beyond certain portions of the edges of the first-named cam for engagement of the extending edges with the fence, the first-named cam having certain portions extending beyond the edges of the second-named cam, for alternative engagement thereof with the fence and a workholder on the cams.

4. A device of the class described comprising a flat base, a workholder on the base, a plurality of cams superposed with relation to each other, means adjustably securing the cams to the workholder at the under side thereof, said cams and workholder as a unit being slidable on the base, a fence on the base, each of said cams having a camming edge and one cam overlapping the other in part only, said cams together engaging the fence by their camming edge and each cam having a separate period of control of a workpiece on the workholder during the movement thereof relative to said fence.

References Cited in the file of this patent UNITED STATESPATENTS 64,922 Strickland May 21, 1867 800,443 Horton Sept. 26, 1905' 1,492,492 Talbot Apr. 29, 1924 1,742,843 Benedict Jan. 7, 1930 1,827,368 Maynard Oct. 13, 1931 2,452,372 Harkness Oct. 26, 1948 2,475,796 Mader July 12, l949 2,540,323 Cross et al Feb. 6, 1951 2,576,707 Ulfves Nov. 27, 1951 2,580,989 Arms Jan. 1, 1952 2,609,643 Shetler Sept. 9, 1952 

